This proposal will examine GABAergic input in a region of the brain necessary for natural and drug related rewards. Understanding the function of the underlying structures which are affected by drugs of abuse, may lead to new preventative measures or treatments. Using the whole cell patch clamp technique, preliminary experiments show that low frequency stimulation (LFS) can greatly potentiate GABAergic input into GABA neurons of the VTA. LTP of GABAergic IPSC's has been shown in of other regions of the brain, rarely through LFS. These examples of LTP occur via many different mechanisms, frequently though activation of PKA. This proposal will test the hypothesis that LFS can induce an activation of PKA that leads to LTP of GABAergic input into the GABA neurons of the VTA though the following aims. Aim 1: To determine the basic properties necessary for LTP of GABAergic input. Aim 2: To determine whether the LTP expression is pre-synaptic or post-synaptic. Aim 3: To determine the molecular mechanism by which this LTP is induced.